遇见数据集

RADARSAT-1 & 2 full archive and tasking

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ESA Earth Online2026-06-22 收录
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"RADARSAT-1&2 full archive and new tasking products are available in several different beam modes. RADARSAT-1 PRODUCTS The Standard beam mode operates with any one of seven beam positions, referred to as S1 to S7. The nominal incidence angle range covered by the full set of Standard beams is from 20 degrees (at the inner edge of S1) to 49 degrees (at the outer edge of S7). Each individual beam covers a minimum ground swath of 100 km within the total 500 km accessibility swath of the full set of Standard beams. The nominal spatial resolution in the range direction is 26 m for S1 at near range to 20 m for S7 at far range. The nominal azimuth resolution is the same, 27 m, for all beam positions. The Wide beam modes are similar to the Standard beams except that the swath width achieved by this beam is 150 km rather than 100 km. As a result, only three Wide beams, W1, W2 and W3 are necessary to provide coverage of almost all of the 500 km swath range. They provide comparable resolution to the standard beam mode, though the increased ground swath coverage is obtained at the expense of a slight reduction in overall image quality. In the Fine beam mode the nominal azimuth resolution is 8.4 m, with range resolution 9.1 m to 7.8 m from F1 to F5. Since the radar operates with a higher sampling rate in this mode than in any of the other beam mode, the ground swath coverage has to be reduced to approximately 50 km in order to keep the downlink signal within its allocated bandwidth. Originally, five Fine beam positions, F1 to F5, were available to cover the far range of the swath with an incidence angle range from 37 to 47 degrees. By modifying timing parameters, 10 new positions have been added with offset ground coverage. Each original Fine beam position can either be shifted closer to or further away from Nadir. In Extended High beam mode six positions, EH1 to EH6, are available for collection of data in the 49 to 60 degree incidence angle range. Since this beam mode operates outside the optimum scan angle range of the SAR antenna, some minor degradation of image quality can be expected when compared with the Standard beam mode. Swath widths are restricted to a nominal 80 km for the inner three positions, and 70 km for the outer three positions. In Extended Low beam mode one position, EL1, is provided for imaging in the incidence angle range 10 to 23 degrees with nominal ground swath coverage of 170 km. As with the Extended High beam mode, some minor degradation of image quality can be expected due to operation of the antenna beyond its optimum elevation angle range. In ScanSAR mode, combinations of two, three or four single beams are used during data collection. Each beam is selected sequentially so that data is collected from a wider swath than possible with a single beam. The beam switching rates are chosen to ensure at least one "look" at the Earth's surface for each beam within the along track illumination time or dwell time of the antenna beam. In practice, the radar beam switching is adjusted to provide two looks per beam. The beam multiplexing inherent in ScanSAR operation reduces the effective sampling rate within each of the component beams; hence the increased swath coverage is obtained at the expense of spatial resolution. The ScanSAR Narrow mode combines two beams (incidence angle range of 20 to 39 degrees) or three beams (incidence angle from 31 to 46 degrees) and provides coverage of a nominal 300 km ground swath, with spatial resolution of 50 m. The ScanSAR Wide mode combines four beams, provides coverage of either 500 km (with incidence angle range of 20 to 49 degrees) or 450 km (incidence angle range from 20 to 46 degrees) nominal ground swaths depending on the beam combination. Beam Mode| Product| Ground coverage (km2)| Nominal resolution (m)| Polarisation| ScanSAR wide| SCW, SCF, SCS| 500 x 500| 100| Single and dual| ScanSAR narrow| SCN, SCF, SCS| 300 x 300| 60| Single and dual| Wide| SGF, SGX, SLC, SSG, SPG| 150 x 150| 24| Single and dual| Standard| SGF, SGX, SLC, SSG, SPG| 100 x 100| 24| Single| Extended low| SGF, SGX, SLC, SSG, SPG| 170 x 170| 24| Single| Extended high| SGF, SGX, SLC, SSG, SPG| 75 x 75| 24| Single| Fine| SGF, SGX, SLC, SSG, SPG| 50 x 50| 8| Single| RADARSAT-2 PRODUCTS The Standard Beam Mode allows imaging over a wide range of incidence angles with a set of image quality characteristics which provides a balance between fine resolution and wide coverage, and between spatial and radiometric resolutions. Standard Beam Mode operates with any one of eight beams, referred to as S1 to S8. The nominal incidence angle range covered by the full set of beams is 20 degrees (at the inner edge of S1) to 52 degrees (at the outer edge of S8). Each individual beam covers a nominal ground swath of 100 km within the total standard beam accessibility swath of more than 500 km. The Wide Swath Beam Mode allows imaging of wider swaths than Standard Beam Mode, but at the expense

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